Project Summary This submission is prepared in response to RFA-ES-15-013, which will establish a National Institute of Environmental Health Sciences - Nanotechnology Health Implications Research (NHIR) Consortium: Comprehensive Evaluation of Interactions Between Engineered Nanomaterials (ENMs) and Biological System U01s. The NHIR Consortium will collaborate to investigate the interaction between ENMs and biological systems to provide comprehensive response profiles of ENM exposures to guide development of benign ENMs and support safe and sustainable use of nanotechnology. The aim of this proposal is to investigate Consortium-selected ENMs, with a broad range of physicochemical properties, to reveal how early life ENM exposure impacts neurobehavioral and cardiovascular outcomes and cause changes in biochemistry. The developing neonate has immature gastrointestinal function, with a developing barrier function, that may allow greater uptake of ENMs than in an adult. The developing brain can be impacted by exposure to chemicals both directly and indirectly. The cardiovascular system has also been shown to be particularly sensitive to the effects of ENMs. The project will consist of three inter-related areas of investigation with the following aims: 1. To investigate the impact of ENMs on the integrity and permeability of the intestinal barrier in vitro. We will test the Consortium-selected ENMs in two well-established models of the small intestine using 1) enterocytes and goblet cells, and 2) enterocytes and M cells. 2. To determine the ENM tissue distribution and cellular localization in exposed neonatal and juvenile rats with determination of neurobehavioral and cardiovascular effects. The biological response to ENMs will be studied in female and male neonatal and juvenile rats with daily ENMs administered orally from postnatal day (PND) 2-20, and euthanized at PND 4, 9, and 21. Comprehensive assessment of the ENM tissue distribution, functional neurobehavioral observations, cardiovascular measurements, neurotransmitter measurement, and untargeted and targeted metabolomics analysis (aim 3) will be conducted on PND 4, 9 and 21. 3. To characterize perturbations in biochemical profiles of serum, brain tissue, and cecal contents associated with ENM exposure, and with neurological and cardiovascular assessments. Studies will focus on determining how ENMs perturb the biochemical profiles of the serum, brain tissue, and cecal contents of male and female rat pups. Assessments will include the use of NMR metabolomics, a 16 channel ECD CoulArray to simultaneously quantitate 20 neurotransmitters, and a quantitative assay for 188 compounds including acylcarnitines, amino acids, biogenic amines, hexose, glycerophospholipids, phosphatidylcholines, and sphingolipids.